Abstract: Sand-based products are regularly used as footing material on indoor equestrian arenas, creating a potential occupational exposure risk for respirable crystalline silica (RCS) for equestrian workers training and exercising horses in these environments. The objective of this study was to evaluate an equestrian worker s personal RCS and respirable dust (RD) exposure. Sixteen personal full-shift RD measurements were collected from an equestrian worker and analysed for RD, quartz and cristobalite. Geometric mean exposures of 0.12 mg m−3 and 0.02 mg m−3 were calculated for RD and RCS concentrations, respectively. RCS exposures of between 0.01 to 0.09 mg m−3 were measured on days when the indoor arena surface was not watered, compared to lower exposures (This research was funded by the MSc Occupational and Environmental Health & Safety programme of
the National University of Ireland, Galwa